Credit cards are widely used for purchasing products and services. Conventionally, a credit card is swiped through a magnetic stripe reader connected to a point-of-purchase terminal. The magnetic stripe reader reads the customer's account information embedded in a magnetic stripe on the credit card and transmits the data of purchase transaction electronically to the credit card issuer's communication network for purchase authorization. The approval or rejection of the credit card purchase is electronically transmitted back to the point-of-purchase terminal. At the point-of-purchase terminal, a store clerk has the customer sign a paper receipt. The store clerk is required to verify the signature on the paper with respect to the signature on the backside of the credit card. However, signature verification is seldom performed for being intrusive and time consuming and it is neglected in the case of using self-service credit card readers, by which credit cards are swiped by credit card owners. Thus, a need exists for a computer-assisted signature verification system for preventing credit card frauds and eliminating physical handling a credit card by a store clerk for inspection. Such need is more pressing because of the growing use of self-service check-out counters in superstores where point-of-purchase terminals are not attended by store clerks. Consequently, it is imperative to have a central signature verification system for the remote authorization of credit card purchases at self-service check-out counters. Furthermore, in the environment of home computers and email systems there is a need for transmitting electronic receipts for enabling customers' book keeping on their home computers. For this purpose, conventionally an email address needs to be pre-registered with a store for transmission of electronic receipts. This requirement is undesirable as the use of the email address becomes out of the card owner's control that may result in unwanted commercial use and junk emails. Therefore, for privacy, personal control and efficiency, it is desirable to have a means of selective transmission of an electronic receipt which is controllable by an customer with automatic input of email address to the email system.
(1) Field of the Invention
The present invention relates to a system of credit card signature verification and electronic receipt transmission. The system involves the use of a credit-card, credit-card reader, digital camera, touch-pad input device, and software control programs interfacing with store database, electronic word processing system and an email system of a computer network.
(2) Related Art
In the prior art a number of patents address computer-assisted signature verification and use of electronic receipts. The methods disclosed heretofore do not adequately satisfy the needs of enforcing signature verification and the privacy of customers' email addresses. The prior art patents relevant to the objectives of the present invention are cited as follows:
U.S. Pat. No. 6,188,309 by Levine deals with the problems of fraud in credit card transactions by providing an intelligent credit card that includes a keypad, a microprocessor and a battery. When using the credit card, a user enters a PIN number on the keypad and only the correct PIN number can activate the credit card. Although the PIN number adds security, the reliability of the intelligent credit card is not ensured as the key pad is not fail-proof and the battery can be out of power. The intelligent credit card is useless when any such malfunction occurs.
Hand-written signatures are widely used for identification of a person due to the uniqueness of a person's signature. Signature characteristics used for comparisons include starting and ending points, strokes, inflections as well as intersection points. Automatic verification of a signature is extremely difficult because of large variation in a person's signature, even more so when signing at an unusual different pace or physical condition.
U.S. Pat. No. 5,559,895 by Lee et al. recognizes that a person's signature changes over time. It uses an adaptive method for signature verification by storing the latest genuine signature in the database. In a verification system the features of a signature are normalized with respect to both time and spatial dimensions; therefore, the information in the database is evolving. Applying to an automated operation, however, the method has a drawback as a current but non-representative signature may be stored and used for the next signature verification. This lack of a constant reference signature may result in confusion and verification errors.
U.S. Pat. No. 5,680,470 by Moussa et al. describes the process of digitizing a signature data and removing irrelevant features for comparing signatures. The signature data comprises a set of pixels in which each pixel has data structure in terms of X, Y coordinates, timing of pen-up/pen-down and related writing pressure. The system uses the normalization of template and test signatures for removing irrelevant factors. In view of the free form nature and inconsistency when writing a signature, it is unreliable for an automatic signature verification system to distinguish irrelevant features of a test signature from meaningful characteristics of a template signature. For a reliable signature verification, it is essential that the full strokes of the test signature and the template signature are displayed and compared.
U.S. Pat. No. 5,251,265 by Dohle et al. describes the process of digitizing a signature image with picture elements. The picture elements are pixels that form a three dimensional information space. In addition to the two dimensional X and Y coordinates, the gray-scale values (blackness) or the optical density is the third dimension of a pixel's properties. For signature verification, the blackness of every pixel which has a range of 256 gray-scale values between black and white is converted into two values, black or white. The conversion utilizes probability values and weighting factors related to the importance of physical factors in signing a signature. A major disadvantage of the probability approach is that a set of weighting factors suitable for describing a person's signature variation over time may not be applicable to other persons.
U.S. Pat. No. 4,985,928 by Campbell et al. relies on the measurement of the optical density of a test signature for comparison with that of a template signature. Because it relies on the optical density, the patent does not address possible errors due to the optical density variations of different types of pens and usage conditions when writing signatures. Also, the patent does not define a characteristic height of a signature for the size normalization.
Introducing the time factor in signing a signature, U.S. Pat. No. 5,828,772 by Kashi et al. discloses a verification method based on signals that represent the speed and direction of the stylus on a signature input device. The information stored is referred to as a stroke-direction code (SDC). The SDC of a signature is obtained by subdividing the signature into a sequence of line segments or a time-ordered array, which are referred to as links between discrete points along the signature. This time-related method is not applicable to the signature verification of a conventional credit card, as the credit card does not contain any SDC information of the template signature on the card.
U.S. Pat. No. 6,076,731 by Terrell describes a magnetic stripe reader using a stationary signature scanner and an electronic transaction system. The swiping action of a credit card provides for simultaneous reading of magnetically encoded data and scanning of an authorized (template) signature on the credit card. For signature verification, a customer inputs a signature on a touch screen or a digitizing tablet. Then the digitized signature is analyzed statistically and compared by stored software to determine the validity of the input (test) signature. Nevertheless, the scanned template signature is obtained by manually swiping the credit card against the stationary scanner by which the swiping motion is not controlled at a constant travel speed. Consequently, the scanned template signature is subject to image distortion due to the variation of swiping speed in the length of the template signature that may lead to verification errors.
U.S. Pat. No. 5,960,100 by Hargoove describes the use of two digital cameras for capturing a thumb print image for verifying the authenticity of a credit card owner. A first camera installed in a credit card reader scans the template thumb print image on the credit card and a second camera is used to scan a test thumb print of a card user. An image comparison mechanism compares the two captured thumb print images. Besides the disadvantage of using two cameras, the method as described does not lead to normalization of thumb print images because of the lack of well defined features in a thumb print for reference for achieving the same orientation and size. Besides, the inking of a user's thumb is an objectionable invasive action.
There is a prior art patent on the use of cameras for capturing signatures in packaging industrial applications. U.S. Pat. No. 5,992,753 by Xu describes the use of a modular camera assembly for generating a composite video signal representing an image of a target area that includes a signature. The imaging assembly has a two-dimensional photosensor array. Although the modular device of this invention captures the image of a signature, it does not distinguish and isolate the signature image from other images in the captured image area for signature normalization and verification.
In a typical purchase transaction, a customer signs his or her name on a receipt with a stylus or on a screen surface of a touch-pad device. A touch-pad device can detect local capacitance changes due to contact pressure. The touch-pad device is connected to a host computer system via a communication link that may include a telephone line, a network or Internet linkage.
A general capacitive-type touch-pad device applicable for signature input is described in U.S. Pat. No. 5,942,733 by Allen et al. The touch pad comprises a substrate material having conductive traces forming capacity sensors with the X direction disposed on a first face and the Y direction disposed on a second face of a compliant material. The compliant material is a sheet of elastic sheet that deforms under pressure and springs back to its original shape when released. A layer of pressure-conductive material is disposed over one of the substrate faces. A protective layer with a conductive coating on its back surface is disposed over the top surface of the pressure-conductive material for protection. When a stylus presses on the surface of a capacitive-type touch-pad sensor, the protective overlayer and compliant material will deform around the area of contact. This has the effect of depressing the conductive layer closer to the X and Y conductive traces of the sensor matrix. The closer proximity of the conductive layer will increase the capacitance measured by the sensor matrix as a contact signal. The magnitude of the contact signal is determined by the degree of the deformation around the stylus.
U.S. Pat. No. 6,002,389 by Kasser allows both touch and pressure gestures to be detected and converted. Instead of a foam-like or silicon-like material, a plurality of small air gaps are utilized for providing capacity variations in response to local contact pressures of a pen or a finger touch. The above two prior patents exemplify the skill in the art and the applicability of capacitive-type touch-pad devices for capturing signature input from pen or stylus contact.
Additionally, U.S. Pat. No. 6,193,152 by Fernando et al. describes a liquid crystal display (“LCD”) that includes a pressure sensitive screen and display that can respond to contact pressure from a passive stylus or pen. A user can write a signature by using a stylus, and simultaneously see the as-written signature displayed on the device. The device includes a built-in three-stripe magnetic card reader. It can be used to conduct paperless transactions. The device enables the merchant to create a profile for each user to communicate purchase information to the user's own computer for accounting purposes. Although the display as described displays a signature on the LCD screen, it does not enable concurrent display of the as-written (test) signature with the (template) signature contained in the credit card for verification. Furthermore, the paperless transaction of this invention requires pre-registration of the email address with the credit card issuer such that the email address is embedded in the magnetic strip. This pre-registration requirement is objectionable to users who prefer privacy and nondisclosure of their email address for commercial use.
Also using a liquid crystal display, the signature verification system of U.S. Pat. No. 6,118,889 by Izuno et al. uses a dedicated pen having the function of applying static charge onto the liquid crystal sheet when writing a signature. After verifying this hand written coordinate information with that of the pre-registered signature, the handwritten signature shown in the liquid display sheet will disappear by itself after a predetermined period of time. The use of a dedicated pen is a severe limitation for this method and the feature of disappearing signature has no advantages compared to a paper receipt having a visible signed signature.
It is desirable to send an electronic receipt to a customer's personal computer via email. A typical electronic receipt includes purchase items along with their prices and grocery codes. U.S. Pat. No. 6,185,542 by Moran et al. describes the process of filling out required forms for pre-registration of an email address with the account number of a store's club card for transmitting purchase transaction data to the email address. When a store computer receives credit card information from a point-of-purchase (POP) terminal, it automatically transmits the transaction data to that email address. The method requires an email address be pre-registered with a closed computer network. Nevertheless, it is desirable to have an electronic receipt transmitted from any stores using an email system without pre-registering the email address. Furthermore, it is not desirable to manually enter the email address by the operator or the credit card user at the POP terminal as it is a time consuming practice.
U.S. Pat. No. 5,739,512 by Tognazzini describes general approaches of delivery of digital (electronic) receipts for travelers for the purpose of not keeping paper receipts. One approach is having a credit card issuer encode an email address on the magnetic stripe of the credit card for enabling purchase receipts to be sent electronically. Alternatively, a smart card is used when electronically signing on a digital receipt and when loading the digital receipt electrically into the smart card. The loaded information on the smart card can be accessed from an appropriate card reader or computer. The loaded information is sent to the credit card issuer when storing the digital receipt to the database, and when using the email address stored in the smart card to send the receipt electronically. The use of a smart card requires an established system protocol for identifying the email address. The user still needs to be verified as the owner of the smart card and the verification process is not addressed by said patent. Additionally, a smart card containing broad-based information is undesirable, as disclosure of one type of information (in credit card use) does not prevent disclosure of other information (such as other bank account data) when the smart card is being processed in a computerized device.
When using an email address for sending electronic receipts, the present invention uses an email address recognition system that reads the email address printed on a label stripe which is attached to the backside of a credit card like the signature label stripe on a conventional credit card. It uses an integrated optical character recognition (OCR) system to identify the signature and the characters of the email address. Then the identified email address is entered to the communication system of a computer network. There are prior art patents that deal with different optical character recognition systems. However, none of the prior art patents are adequately applicable to the need of identifying the email address printed on a credit card.
A typical optical character recognition (OCR) system is provided by U.S. Pat. No. 5,091,968 by Higgins et al. for optically identifying an alphanumeric character on a document. The method comprises the steps of determining a matrix of gray-scale values and X, Y coordinates of pixels, converting the matrix values to binary data, and identifying the test characters by matching the converted binary data with the predetermined binary patterns of the template characters. The OCR system locates and frames each of the characters by searching the stored data for a rise in gray-scale value representing a transition from a light pixel to a dark pixel, vertically from bottom to top along the scan line. When a dark pixel is found, the system checks the character region (the stored data proximate to the dark pixel value) to determine if the dark pixel is part of a character. It checks for the frame size of a character by establishing a segmentation window of sufficient size to frame the character on the document effectively. By means of the segmentation window, a matrix of pixel values most representative of the character is framed. For identifying the next test character, the OCR system proceeds to the next group of stored pixel values representing the region on the document proximate to the proceeding framed character. By the same process the test character in this proximate region is framed and identified. All of the remaining test characters (remaining stored pixel data) are processed in this manner until the end-of-field is detected. However, the optical character recognition of the above invention does not use a normalization process for equating the size and alignment of a test character for ensuring the best match with a template character. Neither feedback means is provided for the correction of the identified characters.
For improving the speed and accuracy of an automatic OCR system, U.S. Pat. No. 5,933,531 by Lorie employs context analysis and operator input on an as-needed basis for error corrections. After character recognition, the context analyzer processes the fields of test characters and evaluates the results of identified contexts of characters which may not be completely recognized. Based on established guidelines and a predetermined level of confidence as criteria, the steps for user-assisted verification and correction may be simplified and omitted to shorten the correction process. However, the process of less than 100% confidence level can lead to errors in identifying the email address. Without the exact correct email address, the email system of the computer network cannot deliver the email to the customer.
Despite the prior art on signature verification and electronic receipts, there has been no system that addresses the need of enforcing signature verification and the selectivity of receiving an electronic receipt. Therefore, it is the objective of the present invention to provide a means of signature verification without physically handling a customer's credit card by a store clerk. It is another objective to provide a means of selectively transmitting an electronic receipt without requiring pre-registering a customer's email address.